Personal care compositions with zinc phosphate active

ABSTRACT

A personal care composition, comprising a soluble zinc polyphosphate complex made by combining ingredients comprising an inorganic zinc salt, a plurality of long chain polyphosphates having 6 or more phosphate polymer units, and an aqueous solvent; wherein the relative amount of inorganic zinc salt and long chain polyphosphates provides a phosphorus to zinc mole ratio of at least 6:1. Also, a method of using the composition for reducing at least one of perspiration or body odor.

BACKGROUND

The present disclosure is directed to a soluble zinc polyphosphatecomplex for use in personal care compositions and methods of making thecomplex.

Zinc compounds are often used in oral care and personal carecompositions. For instance, zinc is known for use in oral care productsas an anti-plaque agent. Compounds such as zinc citrate and zinc oxidehave been added to toothpaste to prevent plaque buildup Zinc salts canalso have other functions related to the body, such as antimicrobialand/or anti-inflammatory effects, which can make them desirable asactive ingredients in personal care products including antiperspirantsand deodorants, among others.

Polyphosphates are also known in the art for use as, for example,chelants, in oral care compositions. In addition, polyphosphates such asdiphosphate (also known as pyrophosphate) and triphosphate are known foruse as anions in antiperspirants, as taught in WO 2013/013903, publishedon Jan. 31, 2013. Longer chain linear polyphosphates (more than 3phosphate units) are susceptible to hydrolysis in aqueous compositions.Upon hydrolysis they are known to form orthophosphates which forminsoluble zinc complexes.

Dentinal hypersensitivity is a painful condition resulting from themovement of liquid in exposed dentin tubules from external stimuli suchas pressure and temperature. One strategy to reduce and/or eliminate thepain resulting from exposed dentin tubules is to form insolubleprecipitates in the tubules in order to physically plug the tubules. Forinstance, Stannous salts have been shown to treat dentinalhypersensitivity by depositing into tubules from neat solutions and fromsimple formulations, as described in U.S. Patent Application PublicationNo. 2009/036432, the disclosure of which is hereby incorporated byreference in its entirety.

Antiperspirant substances often employ aluminum containing actives.These substances reduce the flow of sweat by forming a plug in the sweatduct. However, due to consumer concern about aluminum basedantiperspirant products, Aluminum free antiperspirant actives are indemand.

The discovery of a novel zinc complex that can be used to treat dentinalhypersensitivity and/or that can act as an active in other personal careproducts, such as antiperspirants or deodorants, would be a welcomeaddition to the art.

BRIEF SUMMARY

An embodiment of the present disclosure is directed to a personal carecomposition comprising:

a soluble zinc polyphosphate complex made by combining ingredientscomprising an inorganic zinc salt, a plurality of long chainpolyphosphates having 6 or more phosphate polymer units, and an aqueoussolvent;

wherein the relative amount of inorganic zinc salt and long chainpolyphosphates provides a phosphorus to zinc mole ratio of at least 6:1.

Also, a method of depositing zinc to skin and/or hair of a subject, themethod comprising: providing a personal care composition comprising asoluble zinc polyphosphate complex made by combining ingredientscomprising an inorganic zinc salt, a plurality of long chainpolyphosphates having 6 or more phosphate polymer units, and an aqueoussolvent; and applying the personal care composition to the skin and/orhair of the subject; wherein the relative amount of inorganic zinc saltand long chain polyphosphates provides a phosphorus to zinc mole ratioof at least 6:1.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the disclosure, are intended lotpurposes of illustration only and are not intended to limit the scope ofthe invention.

DETAILED DESCRIPTION

The following description of the preferred embodiment(s) is merelyexemplary it nature and is in no way intended to limit the invention,its application, or uses.

As used throughout, ranges are used as shorthand for describing each andevery value that is within the range. Any value within the range can beselected as the terminus of the range. In addition, all references citedherein are hereby incorporated by referenced in their entireties. In theevent of a conflict in a definition in the present disclosure and thatof a cited reference, the present disclosure controls.

Unless otherwise specified, all percentages and amounts expressed hereinand elsewhere in the specification should be understood to refer topercentages by weight. The amounts given are based on the active weightof the material.

An embodiment of the present disclosure is directed to a soluble zincpolyphosphate complex. The complex is made by combining ingredientscomprising an inorganic zinc salt, a plurality of long chainpolyphosphates having 6 or more phosphate polymer units and an aqueoussolvent. The relative amount of inorganic zinc salt and long chainpolyphosphates provides a phosphorus to zinc mole ratio of at least 6:1,such as about 15:1 to about 25:1.

In one embodiment, the zinc polyphosphate complex has the property ofreduced solubility in water at a first condition of 37° C. and a pH ofabout 7.4 in the presence of 1% by weight Bovine Serum Albumin proteinwhen compared with a second condition of 25° C. and a pH below 5.5, suchas 5.4, in the absence of protein. The reduction in solubility issufficient to allow a desired amount of the soluble zinc polyphosphatecomplex in a saturated solution at the second condition to precipitatefrom the saturated solution at the first condition.

The complex can be made using any suitable inorganic zinc ion source.Examples of suitable inorganic zinc salts include zinc chloride, zincoxide, zinc sulfate, zinc carbonate, zinc fluoride, zinc peroxide, zincphosphate, zinc pyrophosphate, zinc silicate and combinations thereof.

Any polyphosphates having 6 or more phosphate polymer units can beemployed. In an embodiment, long: chain polyphosphate having about 6 toabout 50 phosphate polymer units, such as about 6 to about 30 phosphatepolymer units, can be used. An example of a long chain polyphosphate issodium hexametaphosphate (“SHMP”).

The phosphorus to zinc ratio can be any ratio that results in a solublecomplex at the desired pH in an aqueous solution. In an embodiment, thephosphorus to zinc mole ratio ranges from about 6:1 or more, such asabout 10:1 to about 55:1, such as about 12:1 to about 40:1, or about15:1 to about 25:1 or about 18:1 to about 23:1 or about 20:1 to about23:1, The amount of zinc ion source to phosphate polymer reactantemployed will vary depending on the desired phosphorus to zinc ratio andthe particular reactants used.

In an embodiment, the resulting zinc polyphosphate complex has anaverage of 15 or more P atoms. For example, the zinc polyphosphatecomplex can have an average of about 18 to about 25 P atoms, or about 20to about 23 P atoms. For a zinc polyphosphate complex with a ratio ofP:Zn of about 21:1, it can be predicted that approximately 1 zinc isbound to each phosphate chain on average.

In an embodiment, the zinc polyphosphate complex has a property ofbecoming insoluble in aqueous solution at a pH ranging from above 5.5,such as about 6 or about 6.2 to about 6.5. The zinc polyphosphatecomplex can also have the property of being insoluble at a pH below 6 inaqueous solution in the presence of salivary proteins.

Oral Care Compositions

When used in an oral care product, the soluble zinc and polyphosphatecomplexes of the present disclosure can remain soluble in compositionuntil introduced into the oral cavity of a patient, at which point thecomplexes precipitate on biomaterial surfaces such as dentinal tubules.For example, the soluble zinc polyphosphate complex can diffuse intodentinal tubules and precipitate, to thereby physically occlude thedentinal tubules and prevent dentinal hypersensitivity. In addition, aslong as protein, such as BSA is involved, which may conic from saliva,the zinc precipitate can have relatively strong acid resistance. Basedon these properties, the novel zinc complexes of the present disclosureare potential candidates for, among other things, toothpastes fordentinal hypersensitivity relief.

The zinc polyphosphate complexes of the present disclosure can have oneor more of the following advantages: the ability to remain soluble at apH of 6.1 or less, such as about 5.5 or less; the ability to precipitateat a pH above 5.5, such as about 6.2 or more, the ability to occludedentin tubules and relieve or eliminate dentinal hypersensitivity;and/or the ability to form precipitates that remain insoluble at a pHbelow 6 in the presence of salivary proteins; the ability to in situgenerate a precipitate upon interaction with saliva to effectivelydeliver zinc to the oral surface and provide dentin sensitivity relief,antimicrobial function, in any other benefit that may become apparent;the ability to in situ generate a precipitate upon interaction with skinproteins; or the ability to provide antimicrobial and: oranti-inflammatory effects when applied in a personal care product otherthan oral care products, such as deodorants, or antiperspirants. Thus,this complex has high potential in the oral care and personal carefields.

The present disclosure is also directed to a method of making a solublezinc polyphosphate complex. The method comprises combining inorganiczinc salt; a plurality of long chain polyphosphates having 6 or morephosphate polymer units; and a solvent. As discussed above, the relativeamount of inorganic zinc salt and long chain polyphosphates provides aphosphorus to zinc mole ratio of at least 6:1. The ingredients can bemixed in any suitable order and using any suitable mixing technique withor without heating, so long as the method results in the formation ofthe desired soluble zinc polyphosphate complex.

In certain embodiments, the solvent used in the method is at least onesolvent chosen from water, glycerin, diglycerol (glycerol-2),triglycerol (glycerol-3), quadraglycerol (glycerol-4), sorbitol, andpolyethylene glycol having a weight average molecular weight less than10,000. In one embodiment, the solvent is water. In one embodiment, theamount of solvent is 40 to 90 weight % based on a total weight ofinorganic zinc salt, polyphosphate, and solvent. In other embodiments,the amount of solvent is 70 to 90 weight %, 75 to 85 weight %, or about80 weight %.

The present disclosure is also directed to an oral care composition. Thecomposition comprises a soluble zinc polyphosphate complex made bycombining ingredients comprising an inorganic zinc salt, a plurality oflong chain polyphosphates having 6 or more phosphate polymer units, andan aqueous solvent. The relative amount of inorganic zinc salt and longchain polyphosphates provides a phosphorus to zinc mole ratio of atleast 6:1, as described herein above.

The target amount of zinc to precipitate in the oral care compositioncan be any amount that will reduce dentinal hypersensitivity to adesired degree. In an embodiment, the amount is about 0.1 or more, suchas about 0.1 to about 0.5, or about 0.3 to about 0.4. Suitable amountsof soluble zinc complex can be provided in the oral composition toachieve the desired target precipitate during use.

The oral compositions may be provided in an orally acceptable carrier orvehicle. The carrier can be a liquid, semi-solid, or solid phase, in theform of a mouthrinse, dentifrice (including toothpastes, tooth powders,and prophylaxis pastes), confectionaries including lozenges and gum),medicament, film, or any other form known to one of skill in the art.Selection of specific carrier components is dependent on the desiredproduct form.

In various embodiments, the oral composition has an orally acceptablevehicle that has a pH of about 5.5 to about 10, or about 5.8 or 6 to6.1, 7 or 9. Certain components serve to raise the pH of the oralcomposition. Such compounds include conventional buffers and salts, aswell as chemicals such as the anionic linear polycarboxylates (describedabove) and polyacrylates such as those available from B. F. Goodrich ofCleveland, Ohio and sold under the trade name CARBOPOL® have beenobserved to raise pH when present in oral compositions.

Conventional ingredients can be used to form the carriers listed above.The oral compositions may include other materials in addition to thosecomponents previously described, including for example, surface activeagents, such as surfactants, emulsifiers, and foam modulators, viscositymodifiers and thickeners, humectants, diluents, additional pH modifyingagents, emollients, moisturizers, mouth agents, sweetening agents,flavor agents, colorants, preservatives, solvents, such as water andcombinations thereof. Any given material may serve multiple purposeswithin two or more of such categories of materials. Preferably, suchcarrier materials are selected for compatibility and stability with allof the constituents of the active ingredient.

Useful surface active agents are known in the art, such as thosedisclosed in U.S. Pat. No. 4,894,220, the disclosure of which isincorporated herein by reference in its entirety. Surface active agentscan function as surfactants, emulsifiers foam modulators, and/or activeingredient dispersion agents.

Suitable surface active agents are those that are reasonably stable andfoam throughout a wide pH range. These compounds are known in the art,and include non-soap anionic (e.g., sodium lauryl sulfate (SLS),N-myristoyl, and N-palmitoyl sarcosine), nonionic (e.g., Polysorbate 20(polyoxyethylene 20 sorbitan monolaurate, TWEEN® 20) and Polysorbate 80(polyoxyethylene 20 sorbitan monooleate, TWEEN® 80), Poloxamer 407,available under the trade name PLURONIC® F127 from BASF Corporation),cationic, zwitterionic (e.g., cocoamidopropyl betaine and lauramidopropyl betaine), and amphotetic organic synthetic detergents. In variousembodiments, one or more surface active agents are present in the oralcomposition in the range of about 0.001% to about 5%, or about 0.5% toabout 2.5%. In embodiments where the oral composition comprises anactive ingredient comprising lipophilic active compound(s), the amountof surface active agent can be increased to enable sufficientemulsification of the active ingredients within the carrier of the oralcomposition. The carrier can be, for example, an aqueous carrier.

In an embodiment, the zinc salts can be used in translucent aqueousformulations, such as mouthrinse. In embodiments here the oralcomposition is in the form of a mouthrinse, an exemplary carrier issubstantially liquid. The term “mouthrinse” includes mouthwashes, spraysand the like. In such a preparation the orally acceptable carriertypically has an aqueous phase comprising either water, or a water andalcohol mixture. Further, in various embodiments, the oral carrier cancomprise, for example, a humectant, surfactant, and a pH bufferingagent.

The oral composition may optionally comprise a flavoring agent.Exemplary flavoring substances are known to a skilled artisan, and maybe present in certain embodiments at a concentration of about 0.05% byweight to about 5% by weight.

In embodiments where an oral composition is in the form of aconfectionary, an exemplary carrier may be substantially solid orsemi-solid. Confectionary carriers are known in the art. For a lozenge,the carrier can comprise, for example, a lozenge base material (forexample, comprising, a non-cariogenic polyol and/or starch/sugarderivative), an emulsifier, a lubricant, a flavoring agent, a thickener,and optionally a coating material, Chewing gum carriers generally have achewing, gum base, one or more plasticizing agents, a sweetening agent,and a flavoring agent.

In embodiments where an oral composition is in the form of a film, anexemplary carrier is substantially solid or semi-solid. Such filmcarriers can comprise, for example, a water soluble or dispersible filmforming agent, such as a hydrophilic polymer. Optionally, the filmcarrier may also comprise hydrophobic film forming polymers, either as aremovable backing layer, or mixed with a hydrophilic film formingpolymer. Film carriers optionally comprise plasticizers surface activeagents, tillers, bulking agents, and viscosity modifying agents.

In embodiments where an oral composition is in the form of a dentifrice,an exemplary carrier is substantially semi-solid or a solid. Dentifricescan comprise, for example, surface active agents, humectants, viscositymodifying agents and/or thickeners, abrasives, solvents, such as water,flavoring agents, and sweetening agents. In an embodiment, thedentifrice is a toothpaste.

In embodiments an oral composition is in the form of a medicament suchas a non-abrasive gel or ointment that can be applied to the gingivalsulcus or margin and can be used in conjunction with wound dressings,gauze, films, and the like. Such gels may include both aqueous andnon-aqueous gels. Aqueous gels generally comprise a polymer base, athickener, a humectant, a flavoring agent, a sweetening agent, and asolvent, typically including water.

In various embodiments, the compositions and methods of the presentdisclosure promote oral health in an oral cavity and treat plaque on anoral surface of a mammalian subject. In one embodiment, a method ofproviding one or more oral health benefits to an oral cavity of amammalian subject entails preparing an oral composition as describedherein, where an active ingredient comprises any of the soluble zincpolyphosphate complexes disclosed herein. The prepared oral compositionis contacted with an oral surface within an oral cavity. In addition totreating dentinal hypersensitivity, the oral composition containing theactive ingredient may provide multiple oral health benefits, such asanti-gingivitis, anti-periodontitis, anti-caries, anti-tartar,anti-inflammatory, analgesic, anti-aging, and breath freshening.

Thus, any of the various embodiments of the oral care compositiondescribed above are contacted with or applied regularly to an oralsurface, such as at least one time a day, or on multiple days in a week.

The oral composition of the present disclosure can be made by any of themethods known in the art for combining ingredients to make oral carecompositions. Methods for making the oral compositions comprising asoluble zinc polyphosphate complex, as described herein, are well withinthe ordinary skill of the art.

Personal Care Compositions

The compositions of the present disclosure can be included in a personalcare composition. Examples of such compositions include, but are notlimited to, antiperspirants, deodorants, body washes, shower gels, barsoaps, shampoo, hair conditioners and cosmetics.

For antiperspirant and/or deodorant compositions, the carrier can be anycarrier that is used for antiperspirants and/or deodorants. The carriercan be in the form of a stick, a gel, a roll-on, or an aerosol. Forstick formulations, the carrier may include oils and/or silicones andgelling agents. An example of a formulation can be found inUS2011/0076309A1, which is incorporated herein by reference in itsentirety.

In an embodiment, the personal care compositions, such asantiperspirants and/or deodorants, include a soluble zinc polyphosphatecomplex made by combining ingredients comprising an inorganic zinc salt,a plurality of long chain polyphosphates having 6 or more phosphatepolymer units, and an aqueous solvent. The relative amount of inorganiczinc salt and long chain polyphosphates provides a phosphorus to zincmole ratio is at least 6:1, such as at least 15:1, or at least 18:1,such as about 20:1; and can be any of the other phosphorus to zinc moleratios taught herein for the soluble zinc polyphosphate complex.

The amount of zinc in a personal care composition can be any suitableeffective amount. Suitable amounts of zinc can range, for example, fromabout 0.2% by weight or more, such as about 0.5% to about 10% by weight,relative to the total weight of the composition.

As described above, the zinc polyphosphate complex has the property ofreduced solubility in water at certain temperature and pH conditions,but is soluble at other conditions. In an embodiment, the formulationcan be formulated without added protein, such as BSA. The proteindesired to trigger precipitation can be provided by the sweat of theuser after application of the product.

In an embodiment, the zinc polyphosphate complex can have reducedsolubility at, for example, a condition of 37° C. and a pH of about 7.4in the presence of 1% by weight Bovine Serum Albumin protein whencompared with a second condition of 25° C. and a pH below 5.5 in theabsence of protein. The reduction in solubility can be sufficient toallow a desired amount of the soluble zinc polyphosphate complex in asaturated solution at the second condition to precipitate from thesaturated solution at the first condition, as described above.

In an embodiment, the protein can also be used to enhance the efficacyof other antiperspirant salts comprising a polyvalent cation, forexample antiperspirant complexes of (i) aluminum and optionallyzirconium, (ii) chlorohydrate, and (iii) optionally an amino acid and/orammonium acid, for example glycine and/or trimethylglycine, e.g.,aluminum zirconium tetrachlorohydrex glycine. In an embodiment, theseother antiperspirant salts can be added to the formulations of thepresent disclosure in addition to the zinc polyphosphate complexantiperspirant. In an alternative embodiment, the formulation includesonly very small amounts or is entirely or substantially free of theabove aluminum or zirconium antiperspirant active complexes. Forexample, the formulations can include less than 2 wt %, or less than 0.5wt %, or less than 0.1 wt. %, or less than 0.01 wt. %, or less than0.001 wt. % or less than 0.0001 wt. % aluminum or zirconium, relative tothe total weight of the formulation.

The present disclosure provides antiperspirant products comprising azinc polyphosphate complex antiperspirant active, e.g., any of the zincpolyphosphate complexes discussed herein, as well as methods of makingand using such products. The present disclosure further provides methodsof reducing sweat comprising applying the composition to skin, andmethods of killing bacteria comprising contacting the bacteria with thecomposition.

Optional ingredients that can be included in an antiperspirant and/ordeodorant formulation of the compositions of the present disclosureinclude solvents; water-soluble alcohols such as C₂₋₈ alcohols includingethanol; glycols including propylene glycol, dipropylene tripropyleneglycol and mixtures thereof; glycerides including mono-, di- andtriglycerides; medium to long chain organic acids, alcohols and esters;surfactants including emulsifying and dispersing agents; amino acidsincluding glycine; structurants including thickeners and gelling agents,for example polymers, silicates and silicon dioxide; emollients;fragrances; and colorants including dyes and pigments, if desired, anantiperspirant and/or deodorant agent additional to the soluble zincpolyphosphate complex can be included, for example an odor reducingagent such as a sulfur precipitating agent, e.g., copper gluconate, zincgluconate, zinc citrate, etc.

The antiperspirant compositions can be formulated into topicalantiperspirant and/or deodorant formulations suitable for application toskin, illustratively a stick, a gel, a cream, a roll-on, a soft solid, apowder, a liquid, an emulsion, a suspension, a dispersion or a spray.The composition can comprise a single phase or can be a multi-phasesystem, for example a system comprising a polar phase and an oil phase,optionally in the form of a stable emulsion. The composition can beliquid, semi-solid or solid. The antiperspirant and/or deodorantformulation can be provided in any suitable container such as an aerosolcan, tube or container with a porous cap, roll-on container, bottle,container with an open end, etc.

The compositions can be used in a method to reduce sweating by applyingthe composition to skin. In certain embodiments, the application is toaxilla. Also, the compositions can be used to kill bacteria bycontacting bacteria with the composition comprising the zinc complexesof the present disclosure. In embodiments, other additives for killingbacteria can also be employed in the compositions. Various suitableadditional antimicrobial additives are known in the art.

Thus the present disclosure provides (i) a method for controllingperspiration comprising applying to skin an antiperspirant effectiveamount of a formulation of any embodiment embraced or specificallydescribed herein; and (ii) a method for controlling odor fromperspiration comprises applying to skin a deodorant effective amount ofa formulation of any embodiment embraced or specifically describedherein.

The present invention is further illustrated through the followingnon-limiting example(s).

EXAMPLES Examples 1 to 4

Soluble zinc polyphosphate complex was made by combining 1.277 grams ofZnCl₂, 20.972 grams of SHMP and 82.906 grams of water in a batchsolution. Four samples were made from the batch solution, which arenumbered as examples 1 to 4 in Table 2.

TABLE 2 Example ZnCl2 + SHMP BSA No. solution (g) (g) 1. (pH control) 50 2. (pH raised) 5 0 3. (1% BSA, 4.6769 0.0471 37° C.) 4. (1% BSA, 3.8740.039 RT)

The pH of Example 2 was carefully adjusted from a pH of 4.1 to a pH of6.2 using dilute NaOH, at which point precipitate formed. However whenthe precipitated Example 2 had its pH lowered from 6.2 to 5.13 by addingHCl, the precipitates dissolved and the sample became clear again.

BSA protein was added to the formulations of Examples 3 and 4. Whiteprecipitate formed immediately in both, Example 3 was then aged at 37°C. for 1 hour. Example 4 was aged at room temperature for 1 hour.Precipitate increased in both example formulations with aging. Based onthe color of the solutions, the precipitate increased more in the heatedExample 3. The formation of the precipitate indicates that the zincpolyphosphate made using the zinc chloride and SHMP would be suitablefor treating dentinal hypersensitivity.

Example 5

The acid resistance of the precipitates was tested by adding dilute HCLto the Example 3 formulation to lower the pH from 4.17 to 1.99. Theextent of whiteness of the sample appeared to increase slightly, butoverall the precipitate remained stable as the pH was lowered. Becausethe precipitate did not dissolve at low pH, the test showed that thezinc polyphosphate precipitate is acid resistant in the presence of theBSA protein.

Example 6

A clear mixture of ZnCl₂, SHMP and water from the same batch as Example1 was freeze dried. A white powder resulted. The ability of the solutionto be freeze dried into powder indicates that the complex can be used inboth liquid and solid phase.

The above data from the examples indicates that the soluble zincphosphate mixture can potentially be used in formulations for sensitiveteeth. At a certain molar ratio (approximately 20P:1Zn), soluble zincpolyphosphate solution can be obtained. When this soluble solution ismixed with BSA protein, it quickly starts to precipitate and is ready totreat dentinal tubules, in addition, Zn²⁺ will hydrolyze to amorphouszinc hydroxide at a pH of above 5.5, such as about 7.0 to about 7.4 tophysically block the dentinal tubules. Increased precipitate may form atthe higher pH range of 7.0 to 7.4 as compared with the lower pH range.

Other experiments using an organic zinc reagent and SHMP showed thatwhen a mole ratio of P:Zn is 6.1 or more, such as about 15:1 to about25:1 or about 20:1 to about 23:1, a soluble zinc polyphosphate complexis formed and the solution becomes clear.

In summary, the soluble zinc polyphosphate complex of the presentdisclosure can precipitate at high pH and/or in the presence of protein(e.g., such as found in saliva) and thus can be applied to occludedentinal tubules to provide dentinal hypersensitivity relief. Further,BSA in the above experiments simulates sweat proteins. Based on thedata, it is believed that the complexes of the present disclosure candiffuse into sweat glands and precipitate in combination with protein toblock the sweat ducts of a user, thereby preventing or reducing theamount of sweat coming out of the skin when used as an active ingredientin antiperspirants. In essence, the solubility characteristics of thezinc complex allows it: to readily diffuse into dentin tubules or sweatglands and precipitate, thereby blocking the tubules or glands. Thesolubility can also allow formulation into liquid products, such asmouthwash. Additionally, the soluble Zinc complex can potentially beused to make transparent products.

What is claimed is:
 1. A personal care composition, comprising: asoluble zinc polyphosphate complex made by combining ingredientscomprising zinc chloride and sodium hexametaphosphate; wherein therelative amount of the zinc chloride and sodium hexametaphosphateprovides a phosphorus to zinc mole ratio of 20:1, and wherein thecomposition is an antiperspirant for application to the skin; whereinupon use and contact with proteins in sweat, the soluble zincpolyphosphate complex forms a precipitate which occludes sweat ducts. 2.The personal care composition of claim 1, wherein the zinc polyphosphatecomplex has an average of about 1 zinc atom.